Electric resistance unit



H. F. PRENZLOW.

ELECTRIC RESISTANCE UNIT.

APPLICATION FILED APR-12', 1920.

Patented Dec. 27, 1921.

HERMAN F. PBENZLOW, OF JOHNSON CREEK, WISCONSIN.

ELECTRIC RESISTANCE UNIT.

To all whom it may concern.

Be it known that I, HERMAN F. PRnNznow, a citizen of the United States, and resident of Johnson Creek, in the county of J ei ferson and State of Wisconsin, have invented certain new and useful Improvements in Electric Resistance Units; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates to new and useful improvements in electrical apparatus, and

"pertains particularly to an electrical resistance unit and same.

The primary purposev of the invention 1s the method of forming the to provide a simply constructed resistance unit which can be very inexpensively manufactured and one which will be very efiicient in operation.

In the disposition of resistance units in stoves 'and other electrical heating appliances, a more effective assembling can beobtainedif the terminals of the unit are relatively close together. Heretofore it has been impossible to arrange the .terminals of a heating unit close together without crossing the resistance wire and consequently insulating the same.- Therefore it is also an important object of this invention to provide a resistance unit in which the terminals are relatively close together, while the resistance wire is wound in such a manner that its convolutions do not engage; It is not therefore necessary to insulate the resistance wire.

provide a resistance unit, the terminals of Still another object of the invention is to which are so mounted that the ends of the resistancewire may be easily and positively illustrated an electrical resistance unit ofsecured -thereto, the lead-wires being. also connected therewith in such a manner that movement of the parts thereofadjacent the terminals is prevented.

With these and other objects in view the inventionconsists' in the novel features of construction, combmatlon and arrangement of parts which will hereinafter be more par-' ticularly described and claimed.

Iii the ac: companying drawing Figure 1 represents a plan-view of a re- 5 sistance unit constructed in accordance with my invention. I

Fig. 2 is a detail transverse sectional view showing the manner of securing'one of the lead-wires to a terminal. v

- In the present application I havemerely Specification of Letters Patent. P t t 27, 1 2 Application filed April 12,

1920. Serial No. 373,087.

improved design without attempting to show any arrangement for using the same, and it is understood thatthis invention is capable of being associated with various types of electrical appliances wherein resistance or heating units are necessary. Various forms and sizes may be therefore constructed to accommodate the invention for different uses without departing fromlthe principles or sacrificing any of the advantages thereof.

' The preferred embodiment of the invention comprises asubstantially rectangular form 1 consisting of a plate of mica or other insulating material, a resistance wire 2 being wound therearound and havin its opposite ends connected with termina s 3 and 4 respectively. From Fig. 1 it will be seen that these terminals 3 and 4 are dis osed in,

spaced apart relation adjacent oneongitudinal edge of the form 1 and substantially mid-way the ends thereof. By such an arrangement the resistance unit may be more readily associated with diiferent types of heating-a pliances.

The en portions 5 of the form 1 have the1r opposite side edges provided with spaced notches 6 and 7, the same being arranged alternately with respect to each other. These notches 6 and 7 are formed relatively close together, whereas the intermediate portion 5' of the form 1 has simi-- lar notches 6' and 7', but-the same are spaced considerable distances apart. One" end edge of the form has a notch 8 positioned mid-waythe side ed s; the opposite end has a notch 8' located in relatively the same position. v

In winding a resistance wire on the forni- 1, one end of the same is secured to the terminal 3, then passed across one face of the formto the notch 6' in the upper side edge thereof, thence across the other surface of the form to the notch 6 in the lower edge of the form, the wire being then continuously wound into the notches'6 until the end of the form is reached. This winding has been in the same direction from the termi- 11:11 3 to the end of the form, so in order to reverse the direction of winding, the wire is disposed through the notch 8 to the notch 7 in the upper side edge and thence around the form in the several notches 7 back to the notch 7 in the upper edge. By this ar rangement the convolutions disposed in the notches? are located inbetween the several convolutions positioned in the notches 6.

After the right hand half of the form 1 has been wound with the wire 2, the latter is extended from the upper notch 7' to the lower notch 7 and from there to the innermost notch 7 in the upper side edge of the left hand portion of the form. The notches 7 in this part of the form are then occupied v by the resistance wire by winding the same wherein it will 'be noted that each consists of an eyelet 9disposed from a hole in the therearound until the end is reached where upon the direction of winding is changed as at the opposite end by disposing the wire through the notch 8'. On the return of the wire from this end in which the notch 8' is formed, the notches 6 are occupied, the unattached portion vof the wire being extended resistance unit may be obtained ill this manner but one which will be extremely efficient. in operation and one which is easy to assemble with other parts of electrical appliances. s l

The improved terminals 3 and 4 which are 'used with this unit and which form a part thereof are shown particularly in Fig. 2,

form 1, having its ends upset to secure the ends of the resistance .wire 2.to the ends of the lead-wires 10. In view of the nature of such terminal, it would, under certain conditions tend to rotate, therefore in order to obviate this I extend the lead-wire 10 at;

tached thereto through an form 1.

I claim:

1. An electrical unit'comprising a rectangular form of insulating material having its opposite edges provided with a series of'spaced notches, each end having a opening 11 in the single notch, a pair of terminals ion the form near the center, thereof, and a resistance wire having one endconnected with one terminal and extendin therefrom in spires through alternate notc es to one end notch,

continuing in spires midway between the first mentioned spires and continuing to the other end notch and thence back to the other terminal, said spires from one terminal to the other circumscribing the form continuously in the same general direction and at no point crossing each other on the same side of the form, the two ends of the wire being connected to the terminals at opposite sides of the form.

2. An electrical unit comprising a thin rectangular form of insulating material, a pair of terminals thereon intermediate the ends thereof, and a resistance wire-having one end connected with one of the terminals and its opposite end withthe other terminal, said wire being wound continuously around the forni in one direction from one terminal to one end of said form thence to the opp'o-- site end, thence back to the other terminal, the spires leading from one end of theform to the other alternating with-the spires of the other portions of the wire and nowhere crossing the same;

In testimony that I claim-thefforegoing I have hereunto set my'hand at Milwaukee, in the county of Milwaukee and State of Wisconsin.-

HERMAIT PRENZLGW, 

